Field of the Invention
This invention relates generally to lamp covers and more particularly an illumination cover for a fluorescent lamp for use inside rooms and compartments of railway cars and the like.
Exposed light sources are generally optimal to use to obtain the maximum light energy from the light source. Generally illumination devices are provided with a cover for avoiding the danger of rupture of the lamp therein and the covers are frequently made so that they improve the appearance of the illumination device.
The light transmission factor of opal glass or frosted glass light sources has been in the past in the order of 55%. When such lamps are used additional fluorescent lamps and electric power necessary for the additional lamps is required because of the reduced illumination factor of such devices. This results in substantially uneconomical light sources.
Furthermore the need of increase in fluorescent lamps and fixtures results in an increase in weight in vehicles such as railway cars and increases cost in the manufacture thereof.